Mechanism by which endothelin-1 regulates the differentiation of P19 cells into cardiac conduction cells

Chen Hao; Zhang Wu; Wang Hao; Zhang Heng-yi; Xu Zhi-wei

doi:10.3969/j.issn.2095-4344.0812

Abstract：BACKGROUND: Endothelin-1, as a paracrine cytokine derived from endocardium and vascular endothelial cells, can promote the differentiation and maturation of cardiac conduction cells. OBJECTIVE:To explore the effect of endothelin-1 on P19 cells differentiating into cardiac conduction cells in vitro. METHODS: P19 cells were cultured with 1% dimethyl sulfoxide or 100 nmol/L endothelin-1. Afterwards, the changes of early cardiomyocyte transcription factors MEF2C and GATA4, differentiation markers MHC-α and cTnT, important conduction cell transcription factors Nkx2.5 and Tbx5, and differentiation markers Cx40 and ANP were identified by western blot assay, immunofluorescence and real-time PCR. Specific antagonists of endothelin-1 receptors, and blocking PI3K-AKT-mTOR signaling pathway on the differentiation of P19 cells induced by endothelin-1 were evaluated by real-time PCR. RESULTS AND CONCLUSION: Endothelin-1 significantly up-regulated the levels of early cardiac transcription factors, cardiomyocyte structure factors and characteristic conduction system markers. Compared with dimethyl sulfoxide, endothelin-1 was prone to enhance the differentiation of cardiac conduction cells derived from P19 cells. Up-regulation of Nkx2.5 and Cx40 by endothelin-1 was mainly attributed to the ETAsignaling pathway. ETBsignaling pathway may be also involved in a negative feedback regulation pathway. The PI3K-AKT-mTOR signaling pathway can play an important role in the differentiation from P19 cells to cardiac conduction cells triggered by endothelin-1.